Date Sorting - Please help

Question

Sir,
I have a requirement.
Table :Price
Columns : Price_id
LOCK_EXPIRE_DATE
RELOCK_EXPIR_DATE
LOCK_EXTEN_EXPIR_DATE
I want to sort based on
LOCK_EXPIRE_DATE, RELOCK_EXPIR_DATE,
LOCK_EXTEN_EXPIR_DATE
eg:
Price_id | LOCK_EXPIRE_DATE | RELOCK_EXPIR_DATE | LOCK_EXTEN_EXPIR_DATE
19 | 12-12-2006 | NULL | NULL
15 | NULL | 15-12-2006 | NULL
14 | NULL | NULL | 11-12-2006
After sorting the above data should come like this,
14 | NULL | NULL | 11-12-2006
19 | 12-12-2006 | NULL | NULL
15 | NULL | 15-12-2006 | NULL
regards
Mathew

Answer 1

Suppose the table contans more than 1000 rows, this method will become difficult.I don't understand. Did you want to sort or not ?
1000 rows is nothing...
Here an example with my more 70000 objects... order with nvl or coalesce or without any function, oracle run a FTS.
SQL> drop table tbl_dt ;
Table dropped.
Elapsed: 00:00:00.02
SQL> create table tbl_dt (price_id number,LOCK_EXPIRE_DATE date,RELOCK_EXPIR_DATE date,LOCK_EXTEN_EXPIR_DATE date);
Table created.
Elapsed: 00:00:00.00
SQL> insert into tbl_dt
  2  select rownum,
  3         decode(sign(dbms_random.random),1,null,sysdate+rownum),
  4         decode(sign(dbms_random.random),1,null,sysdate+rownum),
  5         decode(sign(dbms_random.random),1,null,sysdate+rownum)
  6  from dba_objects;
70882 rows created.
Elapsed: 00:00:16.05
SQL>
SQL> select price_id, LOCK_EXPIRE_DATE,RELOCK_EXPIR_DATE,LOCK_EXTEN_EXPIR_DATE
  2  from tbl_dt
  3  where rownum<15;
  PRICE_ID LOCK_EXP RELOCK_E LOCK_EXT
         1          20/01/07
         2 21/01/07 21/01/07 21/01/07
         3                   22/01/07
         4                   23/01/07
         5 24/01/07          24/01/07
         6 25/01/07          25/01/07
         7          26/01/07
         8
         9                   28/01/07
        10
        11          30/01/07
        12          31/01/07 31/01/07
        13          01/02/07
        14          02/02/07 02/02/07
14 rows selected.
Elapsed: 00:00:00.00
SQL>
SQL> set autot traceonly explain stat
SQL> select Price_id, LOCK_EXPIRE_DATE, RELOCK_EXPIR_DATE, LOCK_EXTEN_EXPIR_DATE
  2  from tbl_dt
  3  order by LOCK_EXPIRE_DATE,RELOCK_EXPIR_DATE,LOCK_EXTEN_EXPIR_DATE;
70882 rows selected.
Elapsed: 00:01:14.03
Execution Plan
   0      SELECT STATEMENT Optimizer=CHOOSE
   1    0   SORT (ORDER BY)
   2    1     TABLE ACCESS (FULL) OF 'TBL_DT'
Statistics
        135  recursive calls
        137  db block gets
        241  consistent gets
        943  physical reads
          0  redo size
    1677989  bytes sent via SQL*Net to client
      33351  bytes received via SQL*Net from client
       4727  SQL*Net roundtrips to/from client
          2  sorts (memory)
          1  sorts (disk)
      70882  rows processed
SQL> select Price_id, LOCK_EXPIRE_DATE, RELOCK_EXPIR_DATE, LOCK_EXTEN_EXPIR_DATE
  2  from tbl_dt
  3  order by nvl(LOCK_EXPIRE_DATE,nvl(RELOCK_EXPIR_DATE,LOCK_EXTEN_EXPIR_DATE));
70882 rows selected.
Elapsed: 00:01:14.06
Execution Plan
   0      SELECT STATEMENT Optimizer=CHOOSE
   1    0   SORT (ORDER BY)
   2    1     TABLE ACCESS (FULL) OF 'TBL_DT'
Statistics
          0  recursive calls
        104  db block gets
        228  consistent gets
       1138  physical reads
          0  redo size
    1624623  bytes sent via SQL*Net to client
      33351  bytes received via SQL*Net from client
       4727  SQL*Net roundtrips to/from client
          0  sorts (memory)
          1  sorts (disk)
      70882  rows processed
SQL>
SQL> select Price_id, LOCK_EXPIRE_DATE, RELOCK_EXPIR_DATE, LOCK_EXTEN_EXPIR_DATE
  2  from tbl_dt
  3  order by coalesce(LOCK_EXPIRE_DATE,RELOCK_EXPIR_DATE,LOCK_EXTEN_EXPIR_DATE);
70882 rows selected.
Elapsed: 00:01:14.05
Execution Plan
   0      SELECT STATEMENT Optimizer=CHOOSE
   1    0   SORT (ORDER BY)
   2    1     TABLE ACCESS (FULL) OF 'TBL_DT'
Statistics
          0  recursive calls
        104  db block gets
        228  consistent gets
       1137  physical reads
          0  redo size
    1624624  bytes sent via SQL*Net to client
      33351  bytes received via SQL*Net from client
       4727  SQL*Net roundtrips to/from client
          0  sorts (memory)
          1  sorts (disk)
      70882  rows processed
SQL> Nicolas.